Nutrition, Food Security, and Health

Measuring Food Insecurity

The most commonly used measurement of food insecurity is undernourishment (chronic hunger), which is the proportion of the population who are unable to meet daily energy requirements for light activities. It is an estimate calculated by the Food and Agriculture Organization (FAO) based on country-level food balance sheets. It does not take nutrient adequacy into account, but has the advantage of being available for almost all countries annually (although with a time lag) and assists in monitoring global trends. In addition, FAO measures food access by asking individuals about their experiences over the last 12 mo, such as whether they ran out of food or skipped meals. The responses are graded from mild to severe food insecurity. This relatively simple monitoring tool, the Food Insecurity Experience Scale , provides timely information to guide decision-making at national and local levels.

In 2017, FAO estimated that about 821 million people, or 10.9% of the world's population, were undernourished, 98% of whom were in developing countries. The majority are rural poor people subsisting on small plots of land or hired as laborers, and urban poor people who lack the means to grow or buy food. Alongside the 0.82 billion people who are underfed are 1.9 billion who are overfed, reflecting global inequalities and the “double burden of malnutrition” in low- and middle-income countries.

Nutrition, Food Security, and Poverty

Household food security tracks income closely. With rising incomes, very poor households first increase their dietary energy intake to avert hunger. If incomes rise further, there is a shift to more expensive staple foods and then to a more varied diet with a greater proportion of energy from animal sources, fruits/vegetables, and fats/sugars, and less from cereals, roots, and tubers. National economic growth tends to be accompanied by reductions in stunting, but economic growth can pass by poor persons if they work in unaffected sectors, or are unable to take advantage of new opportunities because of lack of education, access to credit, or transportation, or if governments do not channel resources accruing from economic growth to healthcare, education, social protection, and other public services and infrastructure. There is good evidence that economic growth reduces poverty but does not necessarily reduce undernutrition.

Food Security and Nutrition Targets

The period of Millennium Development Goals (MDGs) ended in 2015. All developing regions except sub-Saharan Africa achieved the target to halve the proportion of people living in extreme poverty, with the proportion falling from 47% in 1990 to 14% in 2015. Reductions in hunger were broadly consistent with those of poverty reduction, and rates of undernourishment in developing regions fell from 23% in 1990 to 13% in 2015. The prevalence of underweight children (another MDG indicator of “hunger”) fell from 29% in 1990 to 15% in 2015 for the developing regions combined. Rural children are almost twice as likely to be underweight as urban children, and the poorest quintile is almost 3 times as likely to be underweight as the richest quintile.

Eradicating poverty and hunger continue to be core targets of the Sustainable Development Goals , as agreed by 193 countries of the United Nations General Assembly in September 2015, and are to be achieved by 2030. In addition, in 2012 the World Health Assembly agreed to 6 global nutrition targets to be reached by 2025, measured against a 2010 baseline, and the United Nations Secretary-General launched the Zero Hunger Challenge with 5 objectives that “would boost economic growth, reduce poverty and safeguard the environment” and “would foster peace and stability” ( Table 57.1 ).

Future Food Security

Between now and 2050 the world's population is expected to exceed 9 billion, and an increase in food supply of 70–100% will be needed to feed this larger, more urban, and more affluent populace. Over this same period, the world's food supply is expected to diminish unless action is taken. Accelerating the decline in fertility rates and reducing overconsumption are basic but difficult actions to bridge the gap between increasing demand and diminishing supply. Equally challenging actions include limiting climate disruption, increasing the efficiency of food production, reducing waste, and reducing the demand for meat and dairy foods.

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  Limit climate disruption. Drought, floods, and other extreme weather events are becoming more prevalent and destroy crops and livestock, often on a huge scale. Rising sea levels will lead to loss of productive land through inundation and salinization. Acidification of oceans will reduce marine harvests. Because curbing greenhouse gas emissions is essential to minimize climate disruption, the goals are (1) to cut fossil fuel use by at least half of present levels by 2050 so as to reduce carbon dioxide (CO ₂ ) emissions and (2) change livestock husbandry and agronomic practices to reduce methane and nitrous oxide (N ₂ O) emissions.

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  Increase efficiency of food production. Expanding the area of agricultural land to any large extent (e.g., by deforestation) is not a sustainable option because of adverse consequences on ecosystems and biodiversity, although some expansion of food production could be achieved by switching good-quality land away from first-generation biofuels. For example, almost 40% of the U.S. corn harvest in 2016–2017 went to biofuels. Efforts to increase the intensity of production need to be environmentally sustainable. These include optimizing yields by soil and water conservation, removal of technical and financial constraints faced by farmers, and breeding resource-efficient crops and livestock that are also climate resilient and pest/disease resistant.

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  Reduce waste. From 30–40% of food is wasted, between harvesting and the market, during retail, at home, and in the food service industry. Better transport and storage facilities in developing countries, less stringent sell-by dates, lower cosmetic standards for fruits and vegetables, and ending supersized portions would help reduce waste.

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  Change diets. As wealth increases, so does the demand for processed foods, meat, dairy products, and fish. About one third of global cereal production is fed to animals, so reducing consumption of meat from grain-fed livestock and increasing the proportion derived from the most efficient sources (pigs and poultry) would allow more people to be fed from the same amount of land.